Simpson had an “extraordinary” collection of images of himself with knives and a machete and Haye-Elliot also appeared comfortable posing with a blade, he said.

The judge told Simpson: “Music was a big part of your life but it’s clear so was your absolutely chilling addiction to holding and using knives.”

The trial heard the defendants were linked to the CR0 gang in south London.

Jermaine Goupall stabbing court case

The attackers, who included Oliver-Rowland and Benzahi, wore masks or balaclavas when they set out in a Ford Focus to attack rival CR7 gang members.

Prosecutor Mukul Chawla QC described them as “nothing more than a marauding gang of thugs”.

The killing came amid heightened tension between the two gangs fuelled by a series of “taunting” music videos posted online.

Judge Leonard said the killing was aggravated by the fact it involved “significant planning and premeditation”, but said it was “pure chance” that Jermaine was targeted.

Detective Chief Inspector Tony Lynes, who led the investigation, said: “Jermaine’s senseless murder appears to have stemmed from gang rivalry and violence, and we now have a family left utterly devastated and the lives of all involved blighted forever.”